Abstract
In this paper a topology optimization algorithm of thin-walled structural
members for crashworthiness is presented. In structural optimization for crashworthiness the
response surface method with several design variables is often used. However recent
development of computer hardware is making other optimization approaches which require
more computer power such as topology optimization practical. In this study a topology
optimization algorithm of thin-walled structural members subject to impact loads is presented.
As a topology optimization method the density method is used and the work done by the
external loads is employed as the object function. In the density method the element density is
taken as the design variable and material properties such as Young´s modulus, the tangent
modulus or the yield stress are assumed to be power functions of it. In this study, we set the
design variable not on the element but on the node to avoid the checkerboard pattern. The
bilinear shell element, which is widely used for the car crash analysis, is employed in the
crash analysis with the explicit time integration scheme. Sensitivity analysis is conducted
numerically using the history of nodal displacements calculated by the crash analysis. Then
the design variables are updated with the optimality criteria method. Through several
numerical examples it was shown that the present method is useful to design a thin-walled
structure.
Keywords: Topology, Optimization, Crash Analysis, Crashworthiness, Shell Element.